Assessing carbon cycle statements

Steps:

• Evaluate statement 1: The carbon cycle balances CO2 through processes like photosynthesis and respiration, regulating atmospheric levels—correct.
• Evaluate statement 2: Photosynthesis absorbs CO2 and releases O2 (6CO2 + 6H2O → C6H12O6 + 6O2)—CO2 is consumed, not produced—incorrect.
• Evaluate statement 3: Combustion of hydrocarbons (e.g., CH4 + 2O2 → CO2 + 2H2O) requires oxygen as a reactant—correct.
• Identify matching option: Statements 1 and 3 are correct, corresponding to choice B.

Why B is correct:

• It selects the accurate statements, aligning with the carbon cycle's regulatory role and the oxygen requirement in combustion reactions.

Why the others are wrong:

• A includes incorrect statement 2 about CO2 production in photosynthesis.
• C omits correct statement 1 on carbon cycle regulation.
• D includes incorrect statement 2.

Final answer: B